What are eddy currents? Do they affect my tone?
An eddy current is caused when there is a flat piece of metal perpendicular to the magnetic field. The metal doesn't need to be magnetic. These eddy currents are small spirals of current that are generated in the metal surface They work in opposition to the magnetic field that causes them.
This causes an interference in the magnetic field. This causes a disruption in the movement of electrons in the winding wire. This in turn has the potential to cause changes in tone.
What Does it Mean in my Guitar?
If there is metal inside the magnetic field of your pickups, some eddy currents will be present. Examples of this are Telecaster bridge pickups surrounded by an ash tray bridge. Eddy currents are present in the base plate also.
Humbucker baseplates and covers have the potential of causing eddy currents depending on the materials used. Some metal Pickup rings may also cause them.
Do Eddy Currents Affect My tone?
To answer this we need to learn a bit more about them. The strength of an eddy current is affected by a few factors.
1. Strength of the magnet
2. Thickness of the metal
3. Distance from the magnet to the metal.
4. Frequency of the motion of the electrons
5. Resistance of the Metal
The math that goes in to all of this is mind boggling, but the short version is this... The magnet has to be very close to the metal to have any major effect.
Remember also.... When we say "do eddy currents affect my tone?" ask yourself.... compared to what?
The video below will help to illustrate the effects of eddy currents and further explain them.
http://youtu.be/Xg7_za82Sbk
This causes an interference in the magnetic field. This causes a disruption in the movement of electrons in the winding wire. This in turn has the potential to cause changes in tone.
Humbucker baseplates and covers have the potential of causing eddy currents depending on the materials used. Some metal Pickup rings may also cause them.